The first term is alcohol by weight from the gravity drop; FG / 0.794
converts weight to volume using the density of ethanol (0.794 g/mL). It's usually
attributed to a 1995 Zymurgy article, and BeerSmith, Brewer's Friend and
Brewfather all use it. It pulls away from abvSimple above ~7 % ABV,
and it's the more accurate of the two there.
The more accurate formula, and the engine default.
The first term is alcohol by weight from the gravity drop;
FG / 0.794converts weight to volume using the density of ethanol (0.794 g/mL). It's usually attributed to a 1995 Zymurgy article, and BeerSmith, Brewer's Friend and Brewfather all use it. It pulls away from abvSimple above ~7 % ABV, and it's the more accurate of the two there.